The movement of critical components in a laser package results in misalignment of, for example, a laser emitting surface and an optical fiber coupled to it for delivering power to the output of the device. Any misalignment of the emitting surface and the optical fiber reduces output power and could result in device failure. Consequently, a great deal of attention has been focused on laser mounting and packaging to avoid the effect of thermal excursions which causes such misalignment.
One effort has been directed at providing robust heat sinks for removing heat thus lowering the effects of thermal excursions. Another approach is directed at attaching the fiber to several anchoring points along the length of the fiber to avoid transmitting stress to the aligned end of the fiber abutting the laser emitting surface. In spite of such approaches, thermally-induced component movement and the resulting misalignment remain an ongoing problem in the industry.
Also, a common problem in the industry for laser diodes has been their susceptibility to permanent damage followed by a certain failure in an event of even a small amount of current flow in the reverse direction either due to handling or due to irregularities in the power supply. Immunity from these kinds of a common problems is assured by the use of a reverse biased diode.